Rear deraileur of bicycle

ABSTRACT

A rear derailleur of a bicycle includes a fixing portion having a first pivot portion and a second pivot portion, a linkage assembly including a first connecting shaft and a second connecting shaft, a moving portion, a chain guide assembly connected to the moving portion, and a driving assembly. An end of the first connecting shaft is pivotally connected to the first pivot portion via a first pivot. An end of the second connecting shaft is pivotally connected to the second pivot portion via a second pivot. The moving portion has a third pivot portion pivotally connected to the first connecting shaft via a third pivot and a fourth pivot portion pivotally connected to the second connecting shaft via a fourth pivot. The driving assembly is disposed on either the first connecting shaft or the second connecting shaft and drives one of the first to fourth pivots to drive the linkage assembly to pivot.

BACKGROUND OF THE INVENTION Technical Field

The present disclosure is related to a derailleur of a bicycle, and moreparticularly to a rear derailleur of a bicycle.

Description of Related Art

With the prevalence of bicycle leisure activities, bicycles are notsimply commuting tools, but have become tools for leisure sports. Themanufacturing technology of bicycles has been continuously improved forimproving the performance of bicycles, wherein the derailleur is one ofthe main reasons affecting the speed of riding. Taking rear derailleuras an example, a rear derailleur includes a moving frame and aderailleur arm, wherein the moving frame is connected to a frame of abicycle and uses a four-bar linkage. The derailleur arm is connected tothe moving frame. By moving the moving frame to drive the derailleur armto move to change a relative position between a chain and sprockets,thereby to achieve the purpose of shifting gears, enabling the rider toshift gears depending on road conditions and improve riding speed.

A conventional rear derailleur uses a cable to towed the moving frame todrive the derailleur arm to move. In recent years, an electronic rearderailleur has appeared on the market, wherein the electronic rearderailleur uses a motor as a drive, and uses a gear set to transmit thepower of the motor to an output shaft, thereby to rotate the outputshaft to move the moving frame. The electronic rear derailleur has theadvantage of improving shift efficiency, making shifting faster and moreconvenient. However, the following disadvantages still exist.

1) A moving frame of the electronic rear derailleur is located on anoutside of the frame of the bicycle, so that when the moving frame ishit by an external force, the gear set or the motor may be damaged dueto the moving frame being moved in an excessive force, causing the gearcannot be shifted.

2) The motor and the gear set of the electronic rear derailleur aredisposed on an outside of the moving frame, which makes the overall sizeof the electronic rear derailleur too large.

3) Since the electronic rear derailleur is powered by the motor and themotor needs to be powered by an external battery, a battery is installedon the frame of the bicycle (e.g. near the seat tube), and then isconnected to the motor of the electronic rear derailleur via a powercord for providing an electrical energy required for the motor. However,the position of the battery is spaced from the position of electronicrear derailleur by a quite distance, so that the layout of the powercord will cause inconvenience during a process of assembling.

4) In order to achieve the purpose of reusing batteries, the battery isalso designed with a rechargeable battery, wherein a charging interfaceis provided on the rechargeable battery. The external power is suppliedinto the charging interface with a charging cable to charge therechargeable battery. Since the bicycle is used outdoors, sand or watermay enter the charging interface, resulting in poor contact or damage tothe charging interface.

Therefore, the conventional electrical rear derailleur still has roomfor improvements.

In addition, whether it is an electronic rear derailleur or atraditional rear derailleur towed by a steel cable, the moving frame isprovided with a pivot shaft (p-knuckle) connected to the derailleur arm,and a torsional spring is provided on the pivot shaft, wherein thetorsional spring provides torque to the pivot shaft, thereby thederailleur arm can provide a certain tension of the chain, so that thechain and the sprocket can mesh with each other during general riding orshifting. However, when the rider encounters poor road conditions, suchas uneven road surfaces, the derailleur arm may excessively shake orvibrate, which will affect the engagement between the chain and thesprocket or cause a chain drop; or when the derailleur arm is pulled byan external force, after the external force is released, the torque ofthe torsional spring drives the derailleur arm to rebound rapidly, whichwill also cause the derailleur arm to excessively shake or vibrate,affecting the engagement between the chain and the sprocket or cause achain drop.

Therefore, the conventional pivot shaft of the rear derailleur still hasroom for improvements.

BRIEF SUMMARY OF THE INVENTION

In view of the above, the purpose of the present disclosure is toprovide a rear derailleur of a bicycle, which could effectively solvethe aforementioned problems.

The inventive subject matter provides a rear derailleur of a bicycleincluding a fixing portion, a linkage assembly, a moving portion, achain guide assembly, and a driving assembly, wherein the fixing portionis adapted to be connected to a frame of the bicycle. The linkageassembly is pivotally connected to the fixing portion. The movingportion is pivotally connected to the linkage assembly. The chain guideassembly is connected to the moving portion. The driving assemblyincludes a motor, a driving gear assembly, and a clutch assembly,wherein the motor includes an output shaft adapted to drive the drivinggear assembly. The driving gear assembly is connected to the clutchassembly, so that the output shaft of the motor drives the linkageassembly to pivot via the driving gear assembly and the clutch assembly,thereby to drive the moving portion and the chain guide assembly tomove. The clutch assembly is pivotally connected between the fixingportion and the linkage assembly and includes a first clutch member anda second clutch member which is abutted against the first clutch memberin an axial direction of the clutch assembly. The first clutch memberhas a plurality of first clutch teeth extending toward the second clutchmember; the second clutch member has a plurality of second clutch teethextending toward the first clutch member. The second clutch teeth aremeshed with the first clutch teeth. When a relative rotational torquebetween the first clutch member and the second clutch member is greaterthan a predetermined resistance, the first clutch teeth and the secondclutch teeth shift relatively.

With the aforementioned design, the clutch assembly could engage anddisengage power transmission when the linkage assembly is hit by anexternal force, thereby to prevent the driving gear assembly or theoutput shaft of the motor from damaging. In addition, when the movingportion is blocked or is get stuck, the clutch assembly could engage anddisengage power transmission for preventing the motor from overheating.

In addition, the another primary objective of the present disclosure isto provide a rear derailleur of a bicycle including a fixing portion, alinkage assembly, a moving portion, a chain guide assembly, and adriving assembly, wherein the fixing portion is adapted to be connectedto a frame of the bicycle and has a first pivot portion and a secondpivot portion. The linkage assembly includes a first connecting shaftand a second connecting shaft, wherein an end of the first connectingshaft is pivotally connected to the first pivot portion via a firstpivot, and an end of the second connecting shaft is pivotally connectedto the second pivot portion via a second pivot. The moving portion has athird pivot portion and a fourth pivot portion, wherein the third pivotportion is pivotally connected to the first connecting shaft via a thirdpivot, and the fourth pivot portion is pivotally connected to the secondconnecting shaft via a fourth pivot. The chain guide assembly isconnected to the moving portion. The driving assembly is disposed on oneof the first connecting shaft and the second connecting shaft, whereinthe driving assembly includes a motor and a driving gear assembly. Anoutput shaft of the motor is connected to the driving gear assembly. Thedriving gear assembly is adapted to drive one of the first pivot, thesecond pivot, the third pivot, and the fourth pivot to drive the linkageassembly to pivot, thereby to drive the moving portion and the chainguide assembly to move.

By disposing the driving assembly on the linkage assembly, the overallsize of the rear derailleur could be reduced, improving the problem thatthe overall size of the conventional electronic rear derailleur is toolarge.

Moreover, the still another primary objective of the present disclosureis to provide a rear derailleur of a bicycle including a fixing portion,a linkage assembly, a moving portion, a chain guide assembly, and adriving assembly, wherein the fixing portion is adapted to be connectedto a frame of the bicycle. The linkage assembly is pivotally connectedto the fixing portion. The moving portion is pivotally connected to thelinkage assembly. The chain guide assembly is connected to the movingportion. The driving assembly includes a motor and a driving gearassembly, wherein the motor includes an output shaft adapted to drivethe driving gear assembly. The driving gear assembly is connected to thelinkage assembly. The output shaft of the motor drives the linkageassembly to pivot via the driving gear assembly, thereby to drive themoving portion and the chain guide assembly to move. A pivot shaft and adetachable battery module are disposed on the moving portion, whereinthe chain guide assembly is pivotally connected to the pivot shaft, andthe detachable battery module is adapted to provide an electric power tothe motor.

By disposing the battery module on the moving portion of the rearderailleur, the power supplying distance could be shortened, so thatthere is no need to provide the power cord from the frame of the bicycleto the rear derailleur, simplifying the layout of the power cord.

Furthermore, the still another primary objective of the presentdisclosure is to provide a rear derailleur of a bicycle including afixing portion, a linkage assembly, a moving portion, a chain guideassembly, a driving assembly, at least one rechargeable battery a coil,and a wireless charging circuit, wherein the fixing portion is adaptedto be connected to a frame of the bicycle. The linkage assembly ispivotally connected to the fixing portion. The moving portion ispivotally connected to the linkage assembly. The chain guide assembly isconnected to the moving portion. The driving assembly includes a motorand a driving gear assembly, wherein the motor includes an output shaftadapted to drive the driving gear assembly. The driving gear assembly isconnected to the linkage assembly. The output shaft of the motor drivesthe linkage assembly to pivot via the driving gear assembly, thereby todrive the moving portion and the chain guide assembly to move. Therechargeable battery is adapted to provide an electrical energy requiredfor the motor. The coil is adapted to receive an external charging powerand is disposed on one of the fixing portion, the moving portion, andthe linkage assembly. The wireless charging circuit is electricallyconnected to the coil and the rechargeable battery and is adapted toreceive an electric power of the coil for charging the rechargeablebattery.

By disposing the coil for inductive charging on the components of therear derailleur, the rechargeable battery of the rear derailleur couldbe charged more conveniently, without the need to set a charginginterface on the battery module.

Furthermore, the still another primary objective of the presentdisclosure is to provide a rear derailleur of a bicycle including afixing portion, a linkage assembly, a moving portion, a chain guideassembly, and a driving assembly, wherein the fixing portion is adaptedto be connected to a frame of the bicycle. The linkage assembly ispivotally connected to the fixing portion. The moving portion ispivotally connected to the linkage assembly. The chain guide assembly isconnected to the moving portion. The driving assembly is connected tothe linkage assembly and is adapted to drive the linkage assembly topivot, thereby to drive the moving portion and the chain guide assemblyto move. The moving portion includes a housing, a pivot shaft, and adamping member, wherein the housing has a receiving space. The pivotshaft is disposed in the receiving space and is connected to the chainguide assembly. The damping member is disposed between the pivot shaftand an inner wall of the receiving space, and has an outer abuttedsurface abutting against the inner wall of the receiving space.

With the damping member that could provide a damping effect, theswinging speed of the chain guide assembly could be slowed down, therebyto prevent the chain guide assembly from excessive shaking or vibrating,which may cause the chain to jump and affect the engagement between thechain and the sprocket or cause a chain drop.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The present disclosure will be best understood by referring to thefollowing detailed description of some illustrative embodiments inconjunction with the accompanying drawings, in which

FIG. 1 is a perspective view of the rear derailleur according to anembodiment of the present disclosure;

FIG. 2 is a partially exploded view of the rear derailleur according tothe embodiment of the present disclosure;

FIG. 3 is a partially exploded view of the rear derailleur according tothe embodiment of the present disclosure;

FIG. 4 is a partially exploded view of the rear derailleur according tothe embodiment of the present disclosure;

FIG. 5 is a top view of the rear derailleur according to the embodimentof the present disclosure;

FIG. 6 is a schematic view, showing a part of the linkage assembly ofthe rear derailleur according to the embodiment of the presentdisclosure;

FIG. 7 is a sectional view along the 7-7 line in FIG. 5;

FIG. 8 is a partially enlarged view of FIG. 7;

FIG. 9 is a perspective view, showing the motor, the driving gearassembly, and the first pivot of the rear derailleur according to theembodiment of the present disclosure;

FIG. 10 is an exploded view of the first pivot according to theembodiment of the present disclosure;

FIG. 11 is a partially exploded view of the first pivot according to theembodiment of the present disclosure;

FIG. 12 is a partially side view of the moving portion according to theembodiment of the present disclosure;

FIG. 13 is a partially exploded view of the rear derailleur according tothe embodiment of the present disclosure;

FIG. 14 is a sectional view along the 14-14 line in FIG. 12;

FIG. 15 is a partially exploded view of the rear derailleur according tothe embodiment of the present disclosure;

FIG. 16 is a partially exploded view of the rear derailleur according tothe embodiment of the present disclosure;

FIG. 17 is a partially exploded view of the rear derailleur according tothe embodiment of the present disclosure;

FIG. 18 is a partially side view of the moving portion according to theembodiment of the present disclosure;

FIG. 19 is a sectional view along the 19-19 line in FIG. 18;

FIG. 20 is a partially perspective view of the rear derailleur accordingto the embodiment of the present disclosure;

FIG. 21 is a partially perspective view of the rear derailleur accordingto another embodiment of the present disclosure;

FIG. 22 is a partially side view of the rear derailleur according tostill another embodiment of the present disclosure;

FIG. 23 is a partially side view of the rear derailleur according tostill another embodiment of the present disclosure;

FIG. 24 is a side view of the rear derailleur according to still anotherembodiment of the present disclosure;

FIG. 25 is a side view of the rear derailleur according to still anotherembodiment of the present disclosure;

FIG. 26 is a top view of the rear derailleur according to still anotherembodiment of the present disclosure;

FIG. 27 is a side view of the rear derailleur according to still anotherembodiment of the present disclosure; and

FIG. 28 is a side view of the rear derailleur according to still anotherembodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

A rear derailleur 100 of a bicycle according to an embodiment of thepresent disclosure is illustrated in FIG. 1 to FIG. 20, and includes afixing portion 10, a linkage assembly 20, a moving portion 30, a chainguide assembly 40, and a driving assembly 50.

The fixing portion 10 is configured to be connected to a frame (notshown) of the bicycle and is disposed on an outside of a rear sprocketassembly of the bicycle. An end of the linkage assembly 20 is pivotallyconnected to the fixing portion 10, and another end of the linkageassembly 20 is pivotally connected to the moving portion 30. The chainguide assembly 40 is connected to the moving portion 30 and includes acage plate 42 and two guiding wheels 44.

The fixing portion 10 includes a connecting member 11 and a base 12,wherein an end of the connecting member 11 is pivotally connected to thebase 12, and another end of the connecting member 11 is fixed on theframe of the bicycle. The base 12 has a first pivot portion 122 and asecond pivot portion 124, wherein the first pivot portion 122 and thesecond pivot portion 124 are respectively and pivotally connected to thelinkage assembly 20. In the current embodiment, the first pivot portion122 has two opposite first pivot ends 122 a, 122 b, and the second pivotportion 124 has two opposite second pivot ends 124 a and is locatedbetween the first pivot portion 122 and the chain guide assembly 40,wherein the first pivot portion 122 is closer to an outside of thefixing portion 10 which is away from the chain guide assembly 40 thanthe second pivot portion 124. However, the arrangement of the firstpivot portion 122 and the second pivot portion 124 is not a limitationof the present disclosure. In other embodiments, the first pivot portion122 could be disposed between the second pivot portion 124 and the chainguide assembly 40, wherein the second pivot portion 124 is closer to theoutside of the fixing portion 10 than the first pivot portion 122.

More specifically, the base 12 includes a first body 14 and a secondbody 16, wherein the second body 16 is detachably connected to a bottomportion of the first body 14. In the current embodiment, one of thefirst pivot ends (i.e., the first pivot end 122 a, hereafter the firstpivot end 122 a) of the first pivot portion 122 and the second pivotends 124 a of the second pivot portion 124 are disposed on the firstbody 14, and the other first pivot end 122 b (hereafter the first pivotend 122 b) of the first pivot portion 122 is disposed on the second body16.

The moving portion 30 has a third pivot portion 31 and a fourth pivotportion 32, wherein the third pivot portion 31 and the fourth pivotportion 32 are respectively and pivotally connected to the linkageassembly 20. In the current embodiment, the fourth pivot portion 32 is,but not limited to, located between the third pivot portion 31 and thechain guide assembly 40, wherein the third pivot portion 31 is closer tothe outside of the fixing portion 10 than the fourth pivot portion 32.In other embodiments, the third pivot portion 31 could be disposedbetween the fourth pivot portion 32 and the chain guide assembly 40,wherein the fourth pivot portion 32 is closer to the outside of thefixing portion 10 than the third pivot portion 31.

The linkage assembly 20 includes a first connecting shaft 22 and asecond connecting shaft 24, wherein the second connecting shaft 24 islocated between the first connecting shaft 22 and the chain guideassembly 40. An end portion 22 a of the first connecting shaft 22 ispivotally connected to the first pivot portion 122 of the fixing portion10 via a first pivot 511, thereby to dispose the end portion 22 a of thefirst connecting shaft 22 between the first pivot ends 122 a, 122 b. Inother words, the first pivot 511 is disposed between the fixing portion10 and the linkage assembly 20. Another end portion 22 b of the firstconnecting shaft 22 is pivotally connected to the third pivot portion 31of the moving portion 30 via a third pivot 513.

As shown in FIG. 4, an end portion 24 a of the second connecting shaft24 is pivotally connected to the second pivot portion 124 of the fixingportion 10 via a second pivot 512, thereby to dispose the end portion 24a of the second connecting shaft 24 between the second pivot ends 124 aof the second pivot portion 124. Another end portion 24 b of the secondconnecting shaft 24 extends toward the moving portion 30 to form twoopposite pivot ends 241, so that the second connecting shaft 24 issubstantially Y-shaped, wherein the two pivot ends 241 are pivotallyconnected to the fourth pivot portion 32 of the moving portion 30 via afourth pivot 514. In the current embodiment, the fourth pivot 514includes two individual pivot shafts disposed on a same pivot axis.

As shown in FIG. 6 to FIG. 9, the driving assembly 50 includes a motor52, a driving gear assembly 54, and a circuit board 56, wherein anoutput shaft 521 of the motor 52 is connected to the driving gearassembly 54. The driving gear assembly 54 is connected to the linkageassembly 20. The circuit board 56 is electrically connected to the motor52 and is adapted to receive a wired or wireless control signal forcontrolling gear shifting and to control the motor 52 according to thecontrol signal. When the output shaft 521 of the motor 52 rotates, arotation of the output shaft 521 is transmitted by the driving gearassembly 54 to drive the linkage assembly 20 to pivot, thereby to drivethe moving portion 30 and the chain guide assembly 40 to move, achievinga purpose of gear shifting.

The driving assembly 50 could be disposed on the first connecting shaft22 of the linkage assembly 20, and the driving gear assembly 54 isconnected to either the first pivot 511 or the third pivot 513 andcorrespondingly generates a rotating force to the first pivot 511 or thethird pivot 513, thereby to drive the first connecting shaft 22 whichprovides with the driving assembly 50 to shift to make the linkageassembly 20 pivots. Alternatively, the driving assembly 50 could bedisposed on the second connecting shaft 24 of the linkage assembly 20,and the driving gear assembly 54 is connected to either the second pivot512 or the fourth pivot 514 and correspondingly generates a rotatingforce to the second pivot 512 or the fourth pivot 514, thereby to drivethe second connecting shaft 24 which provides with the driving assembly50 to shift to make the linkage assembly 20 pivots.

In the current embodiment, the driving assembly 50 is disposed on thefirst connecting shaft 22 as an example, and the driving assembly 50 isconnected to the first pivot 511. In the current embodiment, the firstconnecting shaft 22 includes a motor bracket 26 and a case 28, whereinthe case 28 is engaged with the motor bracket 26. An end of the motorbracket 26 is pivotally connected to the first pivot portion 122 of thefixing portion 10 via the first pivot 511, and another end of the motorbracket 26 is pivotally connected to the third pivot portion 31 of themoving portion 30 via the third pivot 513. The motor 52 and the drivinggear assembly 54 are disposed in the motor bracket 26. In the currentembodiment, the motor bracket 26 is formed by matching two half casings26 a with each other, wherein the motor bracket 26 has two receivingspaces 262, 264 therein, and the motor 52 and the driving gear assembly54 are respectively disposed in the two receiving spaces 262, 264. Inpractice, the motor bracket 26 could have a merely single receivingspace, and both of the motor 52 and the driving gear assembly 54 aredisposed in the receiving space. In practice, the motor bracket 26 andthe first connecting shaft 22 which provides with the first connectingshaft 22 could be integrally formed as a monolithic unit. In anembodiment that the motor bracket 26 is disposed on the secondconnecting shaft 22, the motor bracket 26 and the second connectingshaft 24 could be integrally formed as a monolithic unit.

As shown in FIG. 8, a counterbore 122 c is provided on one of the firstpivot ends (i.e., the first pivot end 122 a) of the first pivot portion122 of the fixing portion 10, and a through hole 122 d is provided onthe first pivot end 122 b of the fixing portion 10, wherein thecounterbore 122 c and the through hole 122 d are correspondinglydisposed. In addition, referring to FIGS. 1, 2, 8, 11, a firstpositioning hole 122 e which intersects with the through hole 122 d isdisposed at the first pivot end 122 b of the fixing portion 10, and asecond positioning hole 552 d corresponding to the first positioninghole 122 e is disposed at an end of the first pivot 511. Twoperforations 26 b corresponding to the counterbore 122 c and the throughhole 122 d are disposed on one of the ends of the motor bracket 26.During a process of assembling, after the first pivot 511 passes throughthe through hole 122 d of the fixing portion 10 and the perforations 26b of the motor bracket 26, a fixing member 17 passes through the firstpositioning hole 122 e and the second positioning hole 552 d, thereby tofix a relative position between the first positioning hole 122 e and thesecond positioning hole 552 d. In the current embodiment, the fixingmember 17 is a pin. At least one end of the first pivot 511 is fixed tothe first pivot portion 122 of the fixing portion 10, so that the firstpivot 511 could not rotate relative to the fixing portion 10. Forinstance, an end of the first pivot 511 is fixed to the counterbore 122c, and another end of the first pivot 511 is disposed in the throughhole 122 d. In practice, a positioning hole could be disposed on thesecond pivot 512, the third pivot 513, or the fourth pivot 514 which isconnected to the driving gear assembly 54, and a correspondingpositioning hole could be disposed on the second pivot portion 124, thethird pivot portion 31, or the fourth pivot portion 32 which isconnected to the second pivot 512, the third pivot 513, or the fourthpivot 514 connected to the driving gear assembly 54, thereby to fix arelative position between the positioning hole and the correspondingpositioning hole via the fixing member 17.

The driving gear assembly 54 includes a first gear 541, a second gear542, and a worm shaft 543, wherein the first gear 541 fits around theoutput shaft 521 of the motor 52 and is meshed with the second gear 542.An end of the worm shaft 543 is fitted by the second gear 542, andanother end of the worm shaft 543 is meshed with a clutch assembly 55.The clutch assembly 55 is disposed on the first pivot 511 to drive themotor bracket 26 to rotate relative to the first pivot 511, thereby tomake the linkage assembly 20 to pivot and to drive the chain guideassembly 40 to move accordingly, so that a chain of the bicycle could bemeshed with sprockets with different radiuses. In other words, theclutch assembly 55 is disposed at a part of the first connecting shaft22. In other embodiments, the clutch assembly could be disposed on thethird pivot 513 or the fourth pivot 514, wherein the first connectingshaft 22 or the second connecting shaft 24 which provides with thedriving assembly 50 is pivotally connected to the third pivot portion 31or the fourth pivot portion 32 of the moving portion 30 or the firstpivot portion 122 or the second pivot portion 124 of the fixing portion10 via the clutch assembly 55.

The driving assembly 50 includes a magnet 57 and a magnetic sensor 58,wherein the magnet 57 is disposed in the counterbore 122 c of the firstpivot portion 122 of the fixing portion 10 and is located at a first end511 a of the first pivot 511 which is away from the fixing member 17. Inpractice, the magnet 57 could be engaged with the first end 511 a of thefirst pivot 511. The magnetic sensor 58 is disposed on the firstconnecting shaft 22 at where the magnet 57 corresponds to, withoutphysically contacting the magnet 57, wherein a surface of the magnet 57faces the magnetic sensor 58, and another surface of the magnet 57 facesthe first pivot 511. In the current embodiment, the magnetic sensor 58is disposed at a side of the magnet 57 opposite to the first pivot 511and is electrically connected to the circuit board 56. The magneticsensor 58 is adapted to detect a relative position between the magnet 57and the first pivot 511 which provides with the driving assembly 50 andto provide a position signal to the circuit board 56 for performing afeedback control. In the current embodiment, the magnetic sensor 58 is aHall sensor. In practice, if the driving assembly 50 is disposed on thesecond connecting shaft 24, the magnetic sensor 58 could be disposed onthe second connecting shaft 24 which provides with the motor bracket 26.In other embodiments, the magnet 56 could be disposed on an end portionof one of ends of the second pivot 512, the third pivot 513, or thefourth pivot 514 which provides with the clutch assembly 55. Preferably,the magnet 56 is disposed away from the fixing member 17.

As shown in FIG. 9 and FIG. 10, the output shaft 521 of the motor 52 isconnected to the driving gear assembly 54, wherein the driving gearassembly 54 is meshed with the clutch assembly 55, and the clutchassembly 55 is disposed on the first pivot 511. When the output shaft521 of the motor 52 rotates, the motor 52 generates a rotating force tothe clutch assembly 55 via the first gear 541, the second gear 542, andthe worm shaft 543 of the driving gear assembly 54, wherein the rotatingforce is transmitted to the first connecting shaft 22 via the firstpivot 511 which is fixed, so that the first connecting shaft 22 pivotsto make the linkage assembly 20 pivot accordingly, thereby to drive themoving portion 30 and the chain guide assembly 40 to move. When thefirst connecting shaft 22 pivots, the magnetic sensor 58 rotatesrelative to the magnet 57 at the same time, so that the magnetic sensor58 could detect a variation of a relative position of the magnet 57,thereby to figure out a relative position of the chain guide assembly40.

Referring to FIG. 1 to FIG. 4, the motor bracket 26 is engaged with thecase 28 to form a receiving space therein, wherein the motor 52 and thedriving gear assembly 54 are disposed in the receiving space, preventingthe driving assembly 50 from being affected by moisture or dust. Thecase 28 is consisted by a case body 281 and a cover 282, wherein thecase body 281 has a top surface 281 a, a bottom surface 281 b, and areceiving slot 281 c recessing from the top surface 281 a toward thebottom surface 281 b and having an opening on the top surface 281 a. Thecircuit board 56 is disposed in the receiving slot 281 c. The topsurface 281 a of the case body 281 has an extending portion 284extending toward the chain guide assembly 40 and covering the firstpivot end 122 a, wherein the extending portion 284 is located betweenthe magnet 56 and the magnetic sensor 57, and the magnetic sensor 58 islocated above the extending portion 284. A surface of the extendingportion 284 faces the magnet 57, and another surface of the extendingportion 284 faces the magnetic sensor 58, so that the magnetic sensor 58is disposed on the case body 281 at where the magnet 57 corresponds to.The cover 282 is engaged with the case body 281 and covers the topsurface 281 a of the case body 281, the extending portion 284, theopening of the receiving slot 281 c, and the magnetic sensor 58.

By disposing the driving assembly 50 in the linkage assembly 20, anoverall size of the rear derailleur 100 could be reduced.

In order to prevent the driving gear assembly 54 or the output shaft 521of the motor 52 from being damaged due to the linkage assembly 20 is hitby an external force or is blocked which may cause the motor 52generates too much rotating force, the clutch assembly 55 of the drivingassembly 50 includes a first clutch member 551 and a second clutchmember 552 which is abutted against the first clutch member 551 in anaxial direction of the clutch assembly 55, wherein the second clutchmember 552 is meshed with the first clutch member 551, and both thesecond clutch member 552 and the first clutch member 551 fit around ashaft 511 b of the first pivot 511. In the current embodiment, the shaft511 b is formed on the first pivot 511. When an external force isexerted on the second clutch member 552, the second clutch member 552could be engaged and disengaged with the first clutch member 551 toachieve a clutch performance. Referring to FIG. 8 to FIG. 11, in thecurrent embodiment, the first clutch member 551 has a plurality of gearteeth 551 a extending in a radial direction of the first clutch member551 and a plurality of first clutch teeth 551 b extending in an axialdirection of the first clutch member 551; the second clutch member 552has a plurality of second clutch teeth 552 a extending in an axialdirection of the second clutch member 552, wherein the first clutchteeth 551 b extends in a direction toward the second clutch member 552,and the second clutch teeth 552 a extends in a direction toward thefirst clutch member 551. The first clutch member 551 is meshed with theworm shaft 543 via the gear teeth 551 a and is meshed with the secondclutch teeth 552 a of the second clutch member 552 via the first clutchteeth 551 b. In a normal state, the second clutch teeth 552 a is meshedwith the first clutch teeth 551 b without relative movement. When anexternal force or a rotating force which is greater than a predeterminedresistance is exerted on the driving assembly 50 (i.e., when a relativerotational torque between the first clutch member 551 and the secondclutch member 552 is greater than the predetermined resistance), thefirst clutch teeth 551 b and the second clutch teeth 552 a shiftrelatively to release a resistance and to mesh with each other again.

For example, when the linkage assembly 20 is hit by an external forceand a rotational force of the first clutch member 551 is greater thanthe predetermined resistance, the first clutch teeth 551 b and thesecond clutch teeth 552 a slide relatively to prevent the drivingassembly 50 from being damaged. In addition, when a movement of themoving portion 30 is blocked, the first clutch teeth 551 b and thesecond clutch teeth 552 a slide relatively to prevent the motor 52 fromoverheating.

Referring to FIG. 9 and FIG. 10, the clutch assembly 55 further includesan elastic member 553 disposed on a sustained portion 551 c of the firstclutch member 551, wherein the sustained portion 551 c and the firstclutch teeth 551 b face opposite directions. In the current embodiment,the sustained portion 551 c has an annular groove 551 d, wherein theelastic member 553 is disposed in the annular groove 551 d. During aprocess of assembling, the elastic member 553, the first clutch member551, and the second clutch member 552 sequentially fit around the firstpivot 511, wherein an end of the elastic member 553 abuts against abottom of the annular groove 551 d, and another end of the elasticmember 553 abuts against an extending section 511 c extending in aradial direction of the shaft 511 b of the first pivot 511. Theextending section 511 c is received in the annular groove 551 d. In thecurrent embodiment, the elastic member 553 is a plurality of bellevillesprings disposed between the extending section 511 c and the annulargroove 551 d of the first clutch member 551 for providing an adjustablepushing force. When the extending section 511 c is disposed at aposition away from the bottom of the annular groove 551 d, a thresholdforce for making the first clutch member 551 and the second clutchmember 552 shift relatively is smaller (i.e., the predeterminedresistance is smaller); when the extending section 511 c is disposed ata position close to the bottom of the annular groove 551 d, thethreshold force for making the first clutch member 551 and the secondclutch member 552 shift relatively is greater, so that a user couldadjust the threshold force for making the first clutch member 551 andthe second clutch member 552 shift relatively to meet variousrequirements.

The shaft 511 b of the first pivot 511 has a threaded section 511 d onan end opposite to the first end 511 a, and the second clutch member 552has a threaded hole 552 b located at an axial direction of the secondclutch member 552, wherein the threaded section 511 d of the shaft 511 bis screwed with the threaded hole 552 b of the second clutch member 552.The predetermined resistance allowed the first clutch member 551 and thesecond clutch member 552 shift relatively could be adjusted by adjustinga threaded depth between the threaded section 511 d of the shaft 511 band the threaded hole 552 b of the second clutch member 552. In thecurrent embodiment, an end 552 c of the second clutch member 552opposite to the second clutch teeth 552 a is fixed in the through hole122 d. More specifically, the end 552 c of the second clutch member 552opposite to the second clutch teeth 552 a has the second positioninghole 552 d. During a process of assembling, the fixing member 17 passesthrough the first positioning hole 122 e of the first pivot end 122 band the second positioning hole 552 d of the second clutch member 552 torestrict the second clutch member 552 from rotating relative to thefirst pivot end 122 b.

With the aforementioned design, the driving assembly 50 could bedisposed on the first connecting shaft 22 which provides with the motorbracket 26 to provide a rotational force to either the first pivot 511or the third pivot 513; the clutch assembly 55 could be disposed oneither the first pivot 511 or the third pivot 513; alternatively, thedriving assembly 50 could be disposed on the second connecting shaft 24which provides with the motor bracket 26 to provide a rotational forceto either the second pivot 512 or the fourth pivot 514; the clutchassembly 55 could be disposed on either the second pivot 512 or thefourth pivot 514, as long as the linkage assembly 20 could be driven topivot to drive the moving portion 30 and the chain guide assembly 40 tomove.

In an embodiment, the driving assembly 50 could be disposed on thefixing portion 10, wherein the first pivot 511 is fixed to the firstconnecting shaft 22, so that the driving assembly 50 exerts a force onthe first pivot 511 to drive the linkage assembly 20 to pivot;alternatively, the second pivot 512 is fixed to the second connectingshaft 24, so that the driving assembly 50 exerts a force on the secondpivot 512 to drive the linkage assembly 20 to pivot.

In the current embodiment, the chain guide assembly 40 could pivotrelative to the moving portion 30. Referring to FIG. 12 to FIG. 14, themoving portion 30 includes a housing 33 and a rotating assembly 60,wherein the third pivot portion 31 and the fourth pivot portion 32 ofthe moving portion 30 are respectively disposed on the housing 33, andthe housing 33 has a first receiving space 331 and a first cover 332.The rotating assembly 60 is disposed in the first receiving space 331,and the first receiving space 331 is covered by the first cover 332,preventing the rotating assembly 60 from being affected by moisture ordust.

The rotating assembly 60 includes a pivot shaft 61 (p-knuckle), anelastic member 62, a bearing 63, and a damping member 64, wherein an endof the pivot shaft 61 is connected to the chain guide assembly 40. Theelastic member 62 of the rotating assembly 60 fits around the pivotshaft 61, wherein an end of the elastic member 62 of the rotatingassembly 60 is connected to the chain guide assembly 40, thereby toprovide a torque in a first rotation direction D1 to the pivot shaft 61.In the current embodiment, the elastic member 62 is a torsional spring.The damping member 64 is disposed between the pivot shaft 61 and aninner wall of the first receiving space 331. More specifically, thebearing 63 fits around the pivot shaft 61 without physically connectingwith the elastic member 62. The damping member 64 fits around thebearing 63 and has an outer abutted surface 641 a and an inner abuttedsurface 641 b. An inner periphery of the bearing 63 is in contact withthe pivot shaft 61, wherein an outer periphery of the bearing 63 abutsagainst the inner abutted surface 641 b of the damping member 64, andthe outer abutted surface 641 a of the damping member 64 abuts againstthe inner wall of the first receiving space 331. In the currentembodiment, the bearing 63 is a one way bearing. When the rotatingassembly 60 rotates in the first rotation direction D1, the innerperiphery and the outer periphery of the bearing 63 could rotaterelatively. When the rotating assembly 60 rotate in a second rotationdirection D2 opposite to the first rotation direction D1, the innerperiphery and the outer periphery of the bearing 63 could not rotaterelatively, thereby making the damping member 64 provides apredetermined friction for preventing the moving portion 30 fromloosening due to an effect that an external force or a vibration exertson the rotating assembly 60.

More specifically, when the chain guide assembly 40 is driven by thedriving assembly 50 to pivot to be engaged with the sprockets withdifferent radiuses, a position of the chain changes to make the chainguide assembly 40 rotated by a chain tension. At this time, the chainguide assembly 40 drives the rotating assembly 60 to rotate in thesecond rotation direction D2. When the rotating assembly 60 rotates inthe second rotation direction D2, a friction is generated between theinner abutted surface 641 b of the damping member 64 and the bearing 63,and another friction is generated between the outer abutted surface 641a of the damping member 64 and the inner wall of the first receivingspace 331, thereby to provide a damping effect, preventing the chainguide assembly 40 from excessive shaking or vibrating due to a vibrationor an external force which may cause the chain to jump and affect theengagement between the chain and the sprocket or cause a chain drop.

In the current embodiment, the damping member 64 is cylindrical forproviding an abutting force on the bearing 63. In other embodiments, thedamping member 64 could be a plurality of blocks distributed on a radialperiphery of the bearing 63. The damping member 64 could be made ofrubber, polyurethane, or other elastic material which allows the dampingmember 64 to deform in a radial direction of the damping member 64 whenthe damping member 64 is squeezed or pressed.

The first cover 332 of the moving portion 30 constitutes an adjustingmember, wherein the first cover 332 is engaged with the housing 33 andis adapted to axially exerts a force on the damping member 64, so thatthe damping member 64 is pushed to deform in the radial direction of thedamping member 64, thereby to change the friction that the outer abuttedsurface 641 a exerts on the inner wall of the first receiving space 331and to change the friction that the inner abutted surface 641 b exertson the bearing 63, so as to change the friction between the outerabutted surface 641 a of the damping member 64 and the inner wall of thefirst receiving space 331 and to change the friction between the innerabutted surface 641 b of the damping member 64 and the outer peripheryof the bearing 63.

In the current embodiment, the housing 33 has an outer surface 33 a awayfrom the chain guide assembly 40, wherein a mounting hole 333 isdisposed on the outer surface 33 a at where the first cover 332corresponds to, and communicates with the first receiving space 331.During a process of assembling, the first cover 332 enters the firstreceiving space 331 via the mounting hole 333 and is engaged with themounting hole 333 by a threaded portion on the first cover 332. Thefirst cover 332 has an extending portion 332 a extending toward an axialdirection of the chain guide assembly 40, wherein the extending portion332 a of the first cover 332 abuts against an end of the damping member64. By adjusting a relative depth between the first cover 332 and thehousing 33, the extending portion 332 a could be driven to axially pushthe damping member 64, so that the damping member 64 deforms in theradial direction of the damping member 64. In this way, a damping forcegenerated by the damping member 64 could be adjusted by adjusting aposition of the first cover 332 that engages with the mounting hole 333of the housing 33.

In the current embodiment, the first receiving space 331 includes afirst chamber 331 a and a second chamber 331 b, wherein a dividingmember 331 c is disposed between the first chamber 331 a and the secondchamber 331 b and has a through hole 331 d. The first chamber 331 acommunicates with the second chamber 331 b via the through hole 331 d.The first chamber 331 a is located between the second chamber 331 b andthe chain guide assembly 40. During a process of assembling, the elasticmember 62 of the rotating assembly 60 is disposed in the first chamber331 a, wherein an end of the elastic member 62 of the rotating assembly60 is disposed on the chain guide assembly 40, and another end of theelastic member 62 of the rotating assembly 60 is disposed on a surfaceof the dividing member 331 c, and then the pivot shaft 61 passes throughthe elastic member 62 of the rotating assembly 60 and the through hole331 d of the dividing member 331 c; the bearing 63 and the dampingmember 64 are disposed in the second chamber 331 b, wherein the bearing63 fits around the pivot shaft 61, and the damping member 64 fits aroundthe bearing 63, and then the first cover 332 covers the mounting hole333. An end of the damping member 64 abuts against another surface ofthe dividing member 331 c, and another end of the damping member 64abuts against the extending portion 332 a of the first cover 332. Inthis way, the damping force could be adjusted by squeezing the dampingmember 64 via both of the dividing member 331 c and the extendingportion 332 a of the first cover 332 to evenly deforms two ends of thedamping member 64.

In the current embodiment, the pivot shaft 61 includes a first portion611 and a second portion 612, wherein the first portion 611 is connectedto the chain guide assembly 40, and the second portion 612 is detachablyconnected to the first portion 611, and the first portion 611 is screwedwith the second portion 612. The first portion 611 of the pivot shaft 61and the elastic member 62 are disposed in the first chamber 331 a, andthe second portion 612 of the pivot shaft 61 is disposed in the secondchamber 331 b. In addition, the second portion 612 of the pivot shaft 61has a flange 612 a extending in a radial direction of the pivot shaft61, wherein the flange 612 a is adjacent to the dividing member 331 c.When the bearing 63 fits around the second portion 612 of the pivotshaft 61, an end of the bearing 63 faces the flange 612 a, and anotherend of the bearing 63 faces the mounting hole 333. An end of the secondportion 612 has an engaging hole 613 (e.g. a hexagonal hole) for beingengaged with a tool to rotate the second portion 612. When the secondportion 612 screws off in a direction of the mounting hole 333, theflange 612 a abuts against the bearing 63 to push the bearing 63 towardthe mounting hole 333, which facilitates the user to take out thebearing 63.

The first cover 332 has a through hole 332 b disposed corresponding tothe engaging hole 613 of the second portion 612, wherein a diameter ofthe through hole 332 b of the first cover 332 is greater than a diameterof the engaging hole 613. A tool could insert into the engaging hole 613via the through hole 332 b of the first cover 332 to rotate the secondportion 612. In this way, the second portion 612 of the pivot shaft 61could be disengaged from the first portion 611 without detaching thebearing 63 and the damping member 64, which facilitates the user toreplace the worn elastic member 62.

The aforementioned damping structure of the moving portion 30 is notlimited to be applied to the electronic rear derailleur 100 according tothe embodiment of the present disclosure, but could be applied to otherrear derailleurs which are not driven by the motor for providing dampingeffect to the chain guide assembly 40. In other embodiments, the drivingassembly could be connected to the linkage assembly 20 via a cable,thereby to drive the linkage assembly 20 to pivot.

As shown in FIG. 15 to FIG. 20, in the current embodiment, the rearderailleur 100 further includes a detachable battery module 80 forproviding electric power to the motor 52, the circuit board 56, and themagnetic sensor 58.

The battery module 80 is disposed on the moving portion 30. The housing33 of the moving portion 30 further has a second receiving space 334,wherein the battery module 80 is disposed in the second receiving space334 and is electrically connected to the circuit board 56, thereby toprovide electricity to the motor 52 via the circuit board 56. The firstreceiving space 331 and the second receiving space 334 extend indifferent directions without communicating with each other, wherein thesecond receiving space 334 is located on an outer periphery of a wall ofthe first receiving space 331 in the radial direction of the pivot shaft61. In the current embodiment, the second receiving space 334 is closerto a ground than the first receiving space 331 (i.e., the secondreceiving space 334 is lower than the first receiving space 331).Preferably, a minimum thickness T between a wall of the second receivingspace 334 and the wall of the first receiving space 331 is smaller thanor equal to 5 mm.

The housing 33 includes a body 330 and a second cover 335, wherein thebody 330 has the first receiving space 331 and at least a part of thesecond receiving space 334, and the second cover 335 covers the secondreceiving space 334. An outer surface of the housing 33 has an opening336 communicating with the second receiving space 334. In the currentembodiment, the opening 336 of the housing 33 is disposed on a side wallof the housing 33 away from the linkage assembly 20. In otherembodiments, the opening 336 of the housing 33 could be disposed on aside wall (not shown) away from the chain guide assembly 40. The secondcover 335 is engaged with the side wall which provides with the opening336 of the housing 33 and covers the opening 336 of the housing 33. Thesecond cover 335 has a space 335 a which constitutes a part of thesecond receiving space 334. In the current embodiment, a part of thebattery module 80 is disposed in a part of the second receiving space334 of the body 330, and another part of the battery module 80 protrudesout of the opening 336 of the housing 33 and is disposed in the space335 a of the second cover 335.

The housing 33 has an inner surface 33 b (as shown in FIG. 18) facingthe chain guide assembly 40, wherein the inner surface 33 b and theouter surface 33 a of the housing 33 face opposite directions. Thesecond receiving space 334 of the housing 33 is located between theouter surface 33 a of the housing 33 and the inner surface 33 b of thehousing 33. The inner surface 36 b and the chain guide assembly 40 arespaced from each other by a distance L, thereby the battery module 80would not easily collide with the chain. Preferably, the distance Lbetween the inner surface 36 b and the chain guide assembly 40 isgreater than or equal to 1 cm.

The housing 33 has a cord hole 337 (as shown in FIG. 19) communicatingthe second receiving space 334 and outside of the housing 33. Thebattery module 80 includes a battery box 81, two batteries 82, and apower cord 83, wherein the batteries 82 are disposed on a box body 81 aof the battery box 81 and are covered by a box cover 81 b of the batterybox 81. The battery box 81 has a perforation 81 c communicating insidethe battery box 81 and outside the battery box 81, wherein theperforation 81 c corresponds to the cord hole 337. The batteries 82transmits electric power by the power cord 83, wherein the power cord 83is connected to the driving assembly 50 by passing through theperforation 81 c of the battery box 81 and the cord hole 337. Inpractice, the batteries 82 are not limited to be two. In otherembodiments, the battery box 81 could provide with at least one battery82.

As shown in FIG. 20, the case 28 of the first connecting shaft 22 has acord hole 286 communicating inside and outside the case 28 and isadapted to be passed through by the power cord 83, wherein the cord hole286 of the case 28 is adjacent to the first pivot portion 31 of themoving portion 30.

In the current embodiment, the batteries 82 are, but not limited to,rechargeable batteries. The battery module 80 further includes a coil 84and a wireless charging circuit 85, wherein the wireless chargingcircuit 85 is electrically connected to the coil 84 and the batteries82. The coil 84 is adapted to receive an external charging power andconverts the external charging power to electric power to the wirelesscharging circuit 85, and the wireless charging circuit 85 converts theelectric power to electricity and sends the electricity to the batteries82 for charging. The coil 84 has a receiving surface 842 for receivingthe external charging power and is disposed on the fixing portion 10,the linkage assembly 20, or the moving portion 30. Preferably, the coil84 is disposed on a component located away from the chain guide assembly40. The receiving surface 842 of the coil 84 faces an outside directionof the fixing portion 10, the linkage assembly 20, or the moving portion30, so that an interference between a wireless charging device (notshown) and the coil 84 could be reduced during charging, and providing abetter stability when supplying charging power to the coil 84.

In the current embodiment, the wireless charging circuit 85 is locatedinside the battery box 81, and the power cord 83 is electricallyconnected to the wireless charging circuit 85. The coil 84 is disposedon a bottom inside the battery box 81 and is located away from therotating assembly 60, wherein the receiving surface 842 of the coil 84is disposed on an outside direction opposite to the batteries 82 (i.e.,the receiving surface 842 faces downward), thereby the wireless chargingdevice (not shown) could provide charging power to the coil 84 via thehousing 33 below.

In an embodiment shown in FIG. 21, the coil 84 is disposed on a topportion inside the battery box 81, wherein the receiving surface 842 ofthe coil 84 faces an upward direction of the moving portion 30 (i.e.,the outside direction is an upward direction).

In an embodiment shown in FIG. 22, the coil 84 is disposed in the space335 a of the second cover 335, wherein the receiving surface 842 isdisposed on an outside direction away from the linkage assembly 20 andfaces an inner wall of the second cover 335. In an embodiment shown inFIG. 23, the receiving surface 842 of the coil 84 faces an outsidedirection of the moving portion 30 away from the chain guide assembly40.

In an embodiment shown in FIG. 24, the coil 84 is located in thereceiving slot 281 c of the case 28 of the linkage assembly 20, whereinthe receiving surface 842 faces an outside direction of the linkageassembly 20 away from the chain guide assembly 40.

In an embodiment shown in FIG. 25, the batteries 82, the coil 84, andthe wireless charging circuit 85 are disposed in the receiving slot 281c of the case 28 of the linkage assembly 20, wherein the housing 33 ofthe moving portion 30 does not provide with the second chamber.

In an embodiment shown in FIG. 26 which is similar to FIG. 25, the coil84 is disposed inside the cover 282 of the linkage assembly 20, whereinthe receiving surface 842 faces an inner wall of the cover 282 (i.e.,the receiving surface 842 faces an upward direction of the linkageassembly 20).

In an embodiment shown in FIG. 27, the coil 84 is disposed on a bottomof the case 28 of the linkage assembly 20, wherein the receiving surface842 is located away from the cover 282 (i.e., the receiving surface 842faces a downward direction of the linkage assembly 20).

In an embodiment shown in FIG. 28, the fixing portion 10 includes ahousing 12 a, wherein the batteries 82, the wireless charging circuit85, and the coil 84 are disposed in the housing 12 a, and the receivingsurface 842 faces a direction of the fixing portion 10 away from thechain guide assembly 40. In other embodiments, the receiving surface 842of the coil 84 could face an upper direction, a downward direction, oran outside direction of the fixing portion 10 away from the linkageassembly 20.

In conclusion, the rear derailleur of the present disclosure hasfollowing advantages.

1. The clutch assembly 55 which could be disposed on either the firstconnecting shaft 22 or the second connecting shaft 24 could engage anddisengage power transmission when the linkage assembly 20 is hit by anexternal force, thereby to prevent the driving gear assembly 54 or theoutput shaft 521 of the motor 52 from damaging. In addition, when themoving portion 30 is blocked or is get stuck, the clutch assembly 55could engage and disengage power transmission for preventing the motor52 from overheating.

2. The driving assembly 50 is disposed on the linkage assembly 20,thereby the overall size of the rear derailleur 100 could be reduced,improving the problem that the overall size of the conventionalelectronic rear derailleur is too large.

3. The battery module 80 is disposed on the rear derailleur 100, therebythe power supplying distance could be shortened, simplifying the layoutof the power cord 83.

4. By utilizing inductive charging technology and by disposing the coilfor inductive charging on the components of the rear derailleur, therechargeable batteries of the rear derailleur 100 could be charged moreconveniently, without the need to set a charging interface on thebattery module 80, preventing the batteries from damaging due to theworn charging interface.

5. The damping member 64 cooperates with the bearing 63 to provide adamping effect, thereby to slow down the swinging speed of the chainguide assembly 40, preventing the chain from jumping which may affectthe engagement between the chain and the sprockets or cause a chaindrop.

It must be pointed out that the embodiments described above are onlysome embodiments of the present disclosure. All equivalent structureswhich employ the concepts disclosed in this specification and theappended claims should fall within the scope of the present disclosure.

What is claimed is:
 1. A rear derailleur of a bicycle, comprising: a fixing portion which is adapted to be connected to a frame of the bicycle and has a first pivot portion and a second pivot portion; a linkage assembly comprising a first connecting shaft and a second connecting shaft, wherein an end of the first connecting shaft is pivotally connected to the first pivot portion via a first pivot, and an end of the second connecting shaft is pivotally connected to the second pivot portion via a second pivot; a moving portion having a third pivot portion and a fourth pivot portion, wherein the third pivot portion is pivotally connected to the first connecting shaft via a third pivot, and the fourth pivot portion is pivotally connected to the second connecting shaft via a fourth pivot; a chain guide assembly connected to the moving portion; and a driving assembly disposed on one of the first connecting shaft and the second connecting shaft, wherein the driving assembly comprises a motor and a driving gear assembly; an output shaft of the motor is connected to the driving gear assembly; the driving gear assembly is adapted to drive one of the first pivot, the second pivot, the third pivot, and the fourth pivot to drive the linkage assembly to pivot, thereby to drive the moving portion and the chain guide assembly to move.
 2. The rear derailleur of claim 1, wherein the driving assembly is disposed on the first connecting shaft.
 3. The rear derailleur of claim 2, wherein the driving gear assembly is connected to the first pivot.
 4. The rear derailleur of claim 2, wherein the driving gear assembly is connected to the third pivot.
 5. The rear derailleur of claim 1, wherein the driving assembly is disposed on the second connecting shaft.
 6. The rear derailleur of claim 5, wherein the driving gear assembly is connected to the second pivot.
 7. The rear derailleur of claim 5, wherein the driving gear assembly is connected to the fourth pivot.
 8. The rear derailleur of claim 1, further comprising a fixing member, wherein a positioning hole is disposed on one of the first pivot, the second pivot, the third pivot, and the fourth pivot which is connected to the driving gear assembly; another positioning hole is disposed on one of the first pivot portion, the second pivot portion, the third pivot portion, and the fourth pivot portion which is connected to one of the first pivot, the second pivot, the third pivot, and the fourth pivot; the fixing member passes through the positioning hole and the another positioning hole to fix a relative position between the positioning hole and the another positioning hole.
 9. The rear derailleur of claim 1, wherein the linkage assembly comprises a motor bracket disposed on one of the first connecting shaft and the second connecting shaft; the motor is disposed on the motor bracket.
 10. The rear derailleur of claim 9, wherein the motor bracket and one of the first connecting shaft and the second connecting shaft which provides with the motor bracket are integrally formed as a monolithic unit.
 11. The rear derailleur of claim 9, wherein a magnet is disposed on an end of one of the first pivot, the second pivot, the third pivot, and the fourth pivot which provides with the fixing member away from the fixing member; a magnetic sensor is disposed on one of the first connecting shaft and the second connecting shaft which provides with the motor bracket at where the magnet corresponds to.
 12. The rear derailleur of claim 11, wherein the linkage assembly comprises a case engaged with the motor bracket; the magnetic sensor is disposed in the case.
 13. The rear derailleur of claim 12, wherein the case has a receiving slot; the driving assembly comprises a circuit board disposed in the receiving slot; the magnetic sensor is electrically connected to the circuit board.
 14. The rear derailleur of claim 13, wherein the case comprises a case body and a cover; the case body has the receiving slot; the cover is engaged with the case body and close an opening of the receiving slot.
 15. The rear derailleur of claim 14, wherein a top portion of the case body has an extending portion extending to be above the magnet; the magnetic sensor is located above the extending portion; the cover covers the magnetic sensor and the extending portion.
 16. The rear derailleur of claim 9, wherein the motor bracket has at least one receiving space; the motor and the driving gear assembly are disposed in the at least one receiving space.
 17. The rear derailleur of claim 1, wherein a clutch assembly is disposed on one of the first pivot, the second pivot, the third pivot, and the fourth pivot, and comprises a first clutch member and a second clutch member which is abutted against the first clutch member in an axial direction of the clutch assembly; the first clutch member has a plurality of first clutch teeth extending toward the second clutch member; the second clutch member has a plurality of second clutch teeth extending toward the first clutch member; the second clutch teeth is meshed with the first clutch teeth. 